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Flashcards in Chapter 15 Deck (60)
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What are some characteristics of the Atrioventricular Node?

  • Located at the interatrial septum.
  • The AV Node receives the impulse and slow the signal.
  • Serves as a delay signal that allows for ventricular filling.


Where to veins carry blood to?

veins carry blood towards the heart


Which hormones increase blood pressure (BP)?

1. Epinephrine/Norepinephrine –increasesCO and causes vasoconstriction.

     2. Antidiuretic Hormone (ADH)- blood volume


     3. Angiotensin II – “”


     4. Aldosterone – “”


Describe the tunica media of the artery

 Very thick layer composed of smooth muscle cells and elastic fibers.


What is angina pectoris

Chest pain due to a obstruction of cornary arteries 


What would an enlarged Q wave suggest?

myocardial infarction (heart attack) 


What would an enlarge R wave suggest?

Ventricular hypertrophy 

(enlarged ventricle) 


What are characteristics of the arteries

  •  Strong, thick-walled vessels.
  • Blood is under high pressure and high in oxygen; low in carbon dioxide.
  • Branch into arterioles.
  • Contain 3 distinct layers


What structures are associated with the atrioventricular valves?

  • Chordae Tendineae- tendon-like cords that connect the cusps of AV valves to the muscle of the ventricles.  – Prevents cusps from swinging back into the atria.
  • Papillary Muscle – the muscular columns
    that are located on the inner surface of the ventricles.


If blood pressure is too high or low, negative feedback regulation happens. Discuss  the negative feedback that happens. 

  1.  BP is detected by baroreceptors in the carotidartery and/or aorta.
  2. They send an impulse to the Medulla.
  3. Medulla interprets that message and sends asignal to the SA Node which increases ordecreases heart rate, lowering or raising CO and BP.
  4. Vasomotor sends an impulse to the arterioles causing constriction or dilation of vessels to alter BP.


Give characteristics of Tunica Media.(Artery)

Very thick layer composed of smooth muscle cells and elastic fibers.


What is the refractory period?

The time following a contraction when a second contraction cannot be triggered.


Give characteristics of Tunica Interna. (Artery)

Surronds lumen and is composed of a layer of simple squamous. 


Describe the characteristics of the Atrium

  • Represent the upper chambers of the heart.
  • Separated by the interatrial septum.
  • Receives blood (passively) returning to the heart from either the lungs (pulmonary vein) or the body (superior and inferior vena cavae).
  • Atria are thin walled chambers.
  • Atria are covered by auricles, small pouches on the anterior surface of each atrium used to increase capacity.
  • Right atrium receives deoxygenated blood from the superior and inferior vena cavae and the coronary sinus.
  • Left atrium – receives oxygenated blood from the pulmonary veins.


What are the 3 major arteries?

  • Aorta- carries blood from the left ventricle to the body.
  • Pulmonary arteries – carry blood from the right ventricle to the lungs (via the pulmonary trunk).
  • Coronary arteries- carry blood to the myocardium.


What are the three structures of the veins?

1. Tunica Interna– composed of endothelial tissue and a basement membrane.

2. Tunica media – very thin layer of smooth muscle (much thinner than the artery).

3. Tunica externa– contains elastic and collagen fibers.


What are the major role of the arterioles?

 Perform a major role in regulating blood flow to the capillaries…regulates blood pressure.


Discuss the pathway of Cardiac Conduction

Sino-artial node

Atrioventricular  Node

Bundle of His

Bundle Branch

Purkinje Fibers

Ventricular Depolarization  


What are 4 major veins?

  • Superior Vena Cava – brings blood from the head upper limbs.
  • Inferior Vena Cava – brings blood from the trunk and lower limbs.
  • Coronary Sinus –brings blood from the myocardium.  – All the vessels will deposit their blood intro the right atrium.
  • Pulmonary Veins – bring blood from the
    lungs to the left atrium.


Describe Purkinje Fibers

  • Located within the papillary muscles of the ventricles.
  • Conduct the impulse into the mass of ventricular muscle tissue, leading to the contraction of the ventricles.


What is cardiac conduction?

Specialized cardiac tissue that conducts impulses throughout the myocardium and coordinates the events of the cardiac cycle.


What are arteries?

  • Arteries are large vessels that carry blood away from the heart.
  • Carry blood that is high in O2 and low in CO2 (exception: pulmonary artery).


What are some characteristics of the Sinoatrial node?

  • Self-excitatory
  • Located on the posterior right atrium
  • Generates impulses responsible for the heartbeat (Pacemaker)
  • Resting membrane potential of the SA Node ~ 60mV
  • Threshold potential of the SA Node ~ -40mV


What does vasodilation lead to?


leads to increased blood flow = decreased blood pressure.


What is cardiac output?

  • Cardiac Output is the volume of blood pumped by either ventricle in one minute.
  • Cardiac Output = Heart rate (HR) X Stroke Volume (SV)


Discuss the pulomary circuit

Carries blood from the right atrium to the lungs, and back to the left atrium. 


The friction in peripheral resistance (factor that alter BP) is due to what?

  • 1. Blood viscosity – increased viscosity = increased R = increased BP


  •  2. Blood vessel length – Increased length = increased R = increased BP


  • 3. Blood vessel radius- increased radius = decreased R = decreased BP


What are veins?

Thin-walled vessels that carry blood under low pressure and high carbon dioxide concentrations.


What are the 3 layers of the heart?

– 1.  Epicardium – outer layer; protects the heart.

– 2. Myocardium – middle layer; responsible for pumping blood out of the heart chambers.

– 3.  Endocardium – smooth inner lining of the heart chambers and valves; contain the Purkinje fibers.


What is the difference between lipid-soluble and wate-soluble in capillary exchange diffusion?

  • Lipid-soluble substances pass directly through the cell membrane.
  •  Water-soluble substances require assistance to pass the membrane.